This proposal is an application for renewal of the collaborative University of Washington (UW)/Puget Sound Blood Center K12 program to train Scholars in clinical research in benign hematology and transfusion medicine. We will build on our long tradition of excellence in research and clinical care in these disciplines to address the critical shortage of clinician scientists investigating clinical problems in benign hematology and transfusion medicine. The program is led by three highly experienced and successful mentors and researchers and includes a large multidisciplinary group of potential mentors from all areas of benign hematology and transfusion medicine and other disciplines, including biostatistics and clinical outcomes research. Our structured program includes training in clinical hematology and transfusion medicine, research methodologies, scientific writing and presentation, and individualized research projects. The training in research methodologies will be provided in close collaboration with the UW Institute for Translational Health Sciences KL2 Multidisciplinary Clinical Research Career Development Program. Key to our proposed program is a strong mentoring plan, beginning with the entry of the scholars into the program and continuing after the scholars leave the program for the next phase of their careers. A structured scholar recruitment and program evaluation plan is described. Our current K12 program has been successful in training scholars in benign hematology and transfusion medicine - a tradition we plan to continue and strengthen with the current application.